Offshore wind energy plants have to be designed with a flight navigation device, in particular in a manner dependent upon their overall height. In this case a distinction is made between hazard beacons, obstruction lights and blade tip navigation lights. In addition, offshore wind energy plants have to be provided with a shipping navigation light and identification.
The aforesaid identifications are suitable only for identifying the offshore wind energy plants and the region of an offshore wind energy plant farm during the day to helicopters or ships for the purpose of entry or for allowing them to be able to avoid the offshore wind energy plant farm in the case of inadequate visibility. Not all offshore wind energy plants have to be provided with light identification for this purpose. At present it is even desired that as little light as possible should be emitted during normal operation in order to disturb birds or other animals for example as little as possible.
A flight navigation means is known from DE 10 2006 007 536 A1, which is switched on only upon specified signals and thus avoids unnecessary lighting pollution of the environment.
A problem with this reduced identification is that vehicles, in particular ships, which enter the offshore wind energy plant farm in the event of a maritime disaster or a navigation error for example, can lose their bearings in poor visibility and can maneuver in the offshore wind energy plant farm only with a serious risk of collision. Helicopters cannot fly into the offshore wind energy plant farm in poor visibility for recovery or rescue purposes without exposing themselves to serious risk on account of the rotating rotor blades, the unclear orientation of the rotors in the farm and on account of the serious risk of collision with the offshore wind energy plants.